Fabrication and compressive properties of directional porous titanium scaffold by freeze casting TiH2 powders

Porous titanium scaffold has been prepared by freeze casting of TiH2 aqueous slurry for the application of structural core of sandwiches, filters, heat exchangers and bones due to the directional lamellar structure. The effects of freezing temperature and solid content, which are decisive parameter in freezing casting process, on porous structure are revealed. As freezing temperature drops and solid content increases, the porosity ranges from 15% to 73%, wall thickness increases from 8 mu m to more than 15 mu m. Different structures provide different mechanical properties. With the decrease of porosity, the yield strength in the direction parallel to the freezing direction rose from 60 MPa to 286 MPa while Young's modulus is from 0.8 GPa to 11.2 GPa. The fracture mode changes from surface fragmentation to body fragmentation along with partial splitting. The modified Gibson -Ashby formula was used to describe the relationship between the mechanical properties and the relative density. The constant and exponents of mechanical properties with porosity are much higher than the conventional process, which indicated excellent mechanical properties compared with other processes. (c) 2021 Published by Elsevier B.V.

Automated summary

The study found that as the freezing temperature decreases and the solid content increases, the porosity and wall thickness of the porous titanium scaffold increase, leading to improved mechanical properties. The relationship between structure and mechanical properties can be described by a specific formula.